I haven’t find a good way to solve this problem.— Don’t _____ . Anything is possible if you work hard.

Your daughter has two children, doesn’t she?—That’s right; she for ten years.

下列说法有误的一项是（ ）

The water level of the river has increased _________ half a meter since it began to rain 7 days ago

Scientists are convinced ____ the positive effect oflaughter ____ physical and mental health.[ ]